Prognostic significance of diabetes on visit-to-visit ultrafiltration volume variability in chronic hemodialysis patients

Background. Patients receiving chronic hemodialysis (HD) have markedly increased mortality compared with the general population, which is further aggravated by diabetes mellitus (DM). Suboptimal extracellular fluid management contributes to cardiovascular (CV) risk in HD patients. Visit-to-visit ultrafiltration volume variability has emerged as a potential prognostic marker; however, its clinical relevance in patients with diabetes remains unclear. We investigated the association between ultrafiltration volume variability, CV events, and mortality in diabetic and non-diabetic patients undergoing chronic HD. Methods. In this retrospective, single-center study, 173 patients undergoing maintenance HD (mean age 63 ± 13 years; 53% men) were analyzed, including 36 (21%) patients with DM. Ultrafiltration volume variability was assessed over a 12-month exposure period using the standard deviation (UVSD) and coefficient of variation (UVCV). Patients were followed for up to 24 months for all-cause mortality and major adverse CV events (MACE). Patients were stratified according to diabetes status and median UVSD (< 568 vs. ≥568 mL) and UVCV (< 0.29 vs. ≥0.29) values. Multivariable regression analyses were performed to evaluate independent and additive associations. Results. Diabetic patients exhibited significantly higher all-cause mortality and MACE rates compared with non-diabetic patients. Diabetic patients with high ultrafiltration variability had the poorest outcomes. High UVSD and UVCV were associated with increased all-cause mortality and MACE, particularly in patients with DM. After multivariable adjustment, DM (OR 3.78, p = 0.002), high UVSD (OR 1.51, p = 0.008), high UVCV (OR 1.30, p = 0.046), and elevated serum phosphate levels (OR 1.11, p = 0.032) were independently associated with all-cause mortality. MACE were independently associated with DM (OR 3.07, p = 0.030), low hemoglobin (OR 3.03, p = 0.037), and elevated C-reactive protein levels (OR 2.11, p = 0.002). No significant multiplicative interaction was observed, indicating additive risk accumulation. Conclusions. In patients undergoing chronic HD, DM and high visit-to-visit ultrafiltration volume variability indices (UVSD and UVCV) are independently and additively associated with increased all-cause mortality and CV events. These findings emphasize the importance of minimizing ultrafiltration variability and optimizing volume management, particularly in diabetic patients, to potentially reduce CV risk in this high-risk population.